Computing is closing in on a horizon of potentially massive change, again. If you think the last decade of digital innovation brought extraordinary upheaval in our day-to-day lives, well you ain’t seen nothing yet.

The shrinking size and cost of the transistor is what makes our digital products ever more powerful, small and cheap. But this constant shrinking is coming to an end as transistors can only get so small before they stop working properly.

Many scientists and researchers are currently working hard to develop the next leap in computing power, and this leap will be bigger and more shocking that what we’ve already witnessed in the last four decades.

Quantum information is a field within quantum mechanics that may just produce the most incredible force in computing power. The unit of quantum information is something called a qubit. And it’s this qubit that may have the potential to replace the transistor, and provide yet another huge transformation within the digital world.

SmartPlanet spoke with astrophysicist Adam Frank, who takes a special interest in explaining quantum information and its potential.

SmartPlanet: Many might have assumed that the Nobel Prize in Physics for 2012 went to the great minds who discovered the Higgs boson in July of this year. Since, after all, this elusive particle may provide answers to the most fundamental questions about the universe. But the Nobel Prize went to two researchers in a field that many have never even heard of: Quantum information.

So, what exactly did these researchers do and why is it important?

Adam Frank: Quantum information theory is a sub-topic of quantum physics, and it is the theory upon which all of our modern technological wizardry is based on.

And what exactly did they do?

The researchers, David Wineland and Serge Haroche, showed us how to gain very subtle control over measuring and manipulating individual quantum systems. And what that means is being able to trap an individual atom and investigate the inherent weirdness of quantum mechanics with extreme precision.
OK. Maybe we better back up. Could you first explain quantum mechanics?

Quantum mechanics has shown us that the law governing the physical world of a very small size looks nothing like the laws that govern macroscopic objects like beach ball, and cars, and rollercoaster rides.
Things are very weird on a very small size scale in ways that it would take me a long time to list. Let me just list the most important.

OK.

In quantum mechanics there is this idea of superposition. Meaning that in the quantum world things can be in two places at once. Or it can be two things at once. Right now in the macroscopic world we live in a world of “either/or.” So either Republicans are going to win the next election or the Democrats are going to win, but we don’t expect them both to win.

Right.

But in the atomic world everything has the possibility of being in two states at once.

Okay, we might need that point to be unpacked.

So for example, there’s the classic parable of Shrodinger’s Cat where you set up an atomic phenomenon, say a radioactive atom that’s going to decay. And if it does decay it trips a switch, breaks a vial of poison, and you have a cat in a box with this radioactive atom with the poison. But, before you open the box you’ve got a state where the radioactive atom had both decayed and it hasn’t decayed. It’s in both states. That’s what we called superposed.

So before I make a measurement, meaning before I open the box and take a look, the quantum system is in both states at the same time, which of course means that the cat is both alive and dead at the same time. Now there’s nothing weirder than saying that Mr. Shingles is both alive and dead at the same time. It makes no sense to us.

Both exist at the same time and there is no way that we can get around that. So that’s one of the principal weirdnesses of quantum mechanics, this idea of superposition.

Okay, that is weird. Something that can be and not be at the same time. So let’s talk about how this quality of superposition and “quantum information” can impact our world?

Quantum mechanics has suddenly forced us to ask questions like, "Does mind affect reality?" Now, no physicist 300 or 500 years ago would have wondered if mind affected reality. And one interpretation of quantum mechanics is how the observer affects the observed.

So that point leads to another fundamental question that I’m most enamored of: Is quantum mechanics really telling us—not about the world itself—but instead is it telling us about our interaction with the world? So the cool thing, the “quantum information” part, is the ability to apply everything we have learned from information theory and probability statistics to this idea of quantum mechanics.

How do they interact--information theory and quantum mechanics?

Well because of the work of Wineland and Haroche we can formulate questions about quantum mechanics in ways that might be experimentally verifiable. That is what’s really exciting about this. The problem with quantum mechanics is you’ve got all these different interpretations and it’s hard to do an experiment to separate one from the other.

It’s almost as if we’re taking quantum mechanics down from the philosopher’s ladder and we are trying to make it practical?

Exactly. The interpretation of quantum mechanics has sort of lived for the last hundred years in the interstitial domain between physics and philosophy.

The paradox of quantum mechanics is we’ve had this theory for a hundred years, and we still don’t know how to visualize the world it’s describing. And that’s stunning to me.

Einstein had always hoped that underneath all the quantum weirdness we’d find that if you set the variables that would make all the weirdness of quantum mechanics go away.

So now where we’re headed is the possibility that quantum information theory will be able to probe deeper into these weirdnesses and tell us what’s going on.
Can you describe the practical and currently useful implications of quantum information for our day-to-day lives? This of course alludes to quantum computing and its possibilities.

Well first we need to know that the idea of superposition that we talked about earlier is one of the key pieces to making quantum computing work.

A computer functions with bits, that are either zero or one. [This is how information is translated within a computer’s operating system.] But with quantum computing, you’re using the inherent weirdness of quantum mechanics and using those superpositions. So now instead of a bit that’s a zero or one you have a so-called qubit, which can be both zero and one. That simple change leads to an enormous increase in computing power. One way of looking at a superposition is that you have possible worlds. And so what quantum computing does is that we can use those qubits [which can be both a zero and a one] and do calculations in all of the potentially possible worlds.

Wow, so it’s almost like super parallel processing.

Exactly. People have described it that way. It’s sort of like parallel processing in the other possible world.

But on a massive, massive scale.

Right. With quantum computing they can do huge calculations that would be literally be impossible even if you took the fastest computer today and waited the entire age of the universe, thirteen billion years, to solve a difficult problem. A quantum computer might be able to take a problem like that and compute it in a few days.

What will that mean for us?

In some sense quantum computing is the difference between an early computer game in 1982 and what we have today, and then multiply that by a trillion trillion trillion.

We probably can’t imagine what this is going to mean for us. But sometimes I just want to try.

I think arguing by analogy is the best way of doing it. Think of the difference between using an abacus and the world’s most modern super computer.

Right.

It’s that kind of transition that we’re talking about.

I have heard that quantum computers will be terrific at optimization problems, in that they will be able to have an impact on route selections, product recommendations, drug development. What else will quantum computers do for us?

The first place they’re going to make a difference will most likely be in security. Quantum computing changes the rules entirely for encryption. And while it may sound boring, security is profoundly important as we continue to enter our credit card information and store our banking transactions digitally.

But ultimately, once we actually have a quantum computer, people are going to find very dramatic, imaginative ways to use it.

What is the biggest challenge for quantum computing to become an everyday reality?

The whole idea with quantum computing is the system must be retained in the purity of its quantum state. If you disturb it, which is what happens when we take measurements of variables, then the whole thing falls apart.

To take thirty or a thousand qubits and have them do a computation requires them to not decohere or in other words, not fall apart at the quantum state. That’s a big challenge. But people are pursuing this at high speed with all efforts. Jeff Bezos and the CIA have recently announced that they are providing funding to a Canadian-based company, D-Wave Systems, that is entirely focused on overcoming the quantum computing challenge. So there are companies already out there trying to be the first ones to get these working systems together.

Christie Nicholson produces and hosts Scientific American's podcasts 60-Second Mind and 60-Second Science and is an on-air contributor for Slate, Babelgum, Scientific American, Discovery Channel and Science Channel. She has spoken at MIT/Stanford VLAB, SXSW Interactive, the National Science Foundation, the National Research Council, the S...
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